JP7253732B2 - Method for producing tofu using enzyme, composition for coagulating soymilk, coagulant for tofu - Google Patents

Description

TECHNICAL FIELD The present invention relates to a method for producing tofu using an enzyme, etc., in particular, a method for producing an enzymatically emulsified coagulant, a method for producing an enzymatically modified soymilk, an enzymatically emulsified coagulant and/or Alternatively, it relates to a method for producing tofu using enzyme-modified soymilk.

Tofu is produced by adding a coagulant to soymilk to crosslink proteins in the soymilk and gel the soymilk. As a coagulant for tofu, bittern containing magnesium chloride as a main component is well known. Bitter is a fast-acting coagulant and causes soymilk to start coagulating immediately after being added. In particular, when soymilk at a high temperature is used, this characteristic becomes more pronounced. Therefore, in order to diffuse the coagulant evenly in the soymilk and produce tofu of uniform quality, skilled tofu craftsmen are required. Moreover, it has been difficult to stably produce homogeneous tofu because bittern (magnesium chloride), which is said to have particularly good tofu flavor, causes soymilk to coagulate quickly.

Against this background, as a means for realizing mass production of homogeneous tofu, a technology for controlling and delaying the soymilk coagulation time of bittern and other coagulants is required. As one example, an emulsified coagulant (so-called "emulsified bittern"), which is characterized by emulsifying a coagulant using fat and an emulsifier, has already been sold and used (Patent Document 1).

JP-A-2005-130803 JP 2012-254097 A Japanese Patent No. 3654623

The emulsifying coagulant described above exerts an excellent effect from the viewpoint of delaying the coagulation of soymilk. However, since the emulsified coagulant is prepared using an emulsifier such as polyglycerol fatty acid ester, it has the drawback of deteriorating the flavor and taste of tofu due to the emulsifier. Moreover, especially in recent years, consumers tend to avoid foods containing emulsifiers due to the growing health consciousness of consumers. In addition, due to the tendency of tofu producers to pursue differentiated products and added value, standardized flavors tend to be avoided. There is an urgent need to improve these points as well. Therefore, there is a strong demand for the development of a new means for delaying the coagulation of soymilk without using an emulsifier. The coagulation delaying effect was not sufficient and it was difficult to use (Patent Documents 2 and 3).

As a result of intensive studies on the above-mentioned problems, the present inventors have found that by reacting an edible oil and lipase or phospholipase with a coagulant, a coagulant can be obtained without using an emulsifier and regardless of the type of edible oil. can be easily emulsified into a W/O type, and the coagulation of soymilk can be delayed by using the emulsified coagulant. Further, the present inventors have found that a coagulant having a more favorable coagulation retarding effect can be prepared by further adding cyclodextrin during emulsification of the coagulant with edible oil and lipase or phospholipase. Furthermore, the present inventors have found that soymilk modified by the action of lipase or phospholipase has coagulation retarding properties against coagulants, and that coagulants emulsified with lipase or phospholipase and lipase The inventors also found that tofu prepared using modified soymilk has a very smooth texture, and further research based on this finding led to the completion of the present invention.
That is, the present invention is as follows.

[1] A method for producing an emulsified tofu coagulant, comprising allowing either or both of lipase and phospholipase to act on a coagulant and edible oil.
[2] The production method according to [1], wherein the coagulant is one or more selected from the group consisting of magnesium chloride, magnesium sulfate, calcium sulfate, calcium chloride, organic acids, and compositions containing one or more of these. .
[3] The production method according to [1] or [2], which further comprises allowing cyclodextrin to act.
[4] A method for producing soymilk having a characteristic of retarding coagulation, comprising allowing either or both of lipase and phospholipase to act on soymilk.
[5] The production method according to [4], wherein the temperature at which either or both of lipase and phospholipase are allowed to act on soymilk is 50°C to 95°C.
[6] A method for producing tofu, comprising mixing soymilk and an emulsified coagulant produced by the method according to any one of [1] to [3].
[7] A method for producing tofu, which comprises mixing soymilk produced by the method according to [4] or [5] and having a characteristic of retarding coagulation with a coagulant.
[8] Soymilk produced by the method described in [4] or [5] and having a characteristic of delaying coagulation, and emulsified coagulation produced by the method described in any one of [1] to [3] A method for producing tofu, comprising mixing with an agent.
[9] A method of emulsifying a tofu coagulant, which comprises allowing either or both of lipase and phospholipase to act on the coagulant and edible oil.
[10] The method of [9], which further comprises allowing cyclodextrin to act.
[11] The method according to [9] or [10], wherein the edible oil is at least one vegetable oil selected from the group consisting of rice oil, rapeseed oil, and soybean oil.
[12] The coagulant is one or more selected from the group consisting of magnesium chloride, magnesium sulfate, calcium sulfate, calcium chloride, organic acids, and compositions containing one or more of these [9]-[11] A method according to any one of
[13] A method for delaying coagulation of soymilk, which comprises causing either or both of lipase and phospholipase to act on soymilk.
[14] The method according to [13], wherein the temperature at which either or both of lipase and phospholipase are allowed to act on soymilk is 50°C to 95°C.
[15] A composition for retarding coagulation of soymilk for producing tofu, containing either or both of a lipase and a phospholipase.
[16] A coagulant for tofu, comprising either or both of a lipase and a phospholipase, and a coagulant.
[17] The tofu coagulant according to [16], further comprising edible oil.
[18] The tofu coagulant according to [16] or [17], further comprising cyclodextrin.
[19] The tofu coagulant according to any one of [16] to [18], wherein the edible oil is at least one vegetable oil selected from the group consisting of rice oil, rapeseed oil, and soybean oil.
[20] The coagulant is one or more selected from the group consisting of magnesium chloride, magnesium sulfate, calcium sulfate, calcium chloride, organic acids, and compositions containing one or more of these [16]-[19] The coagulant for tofu according to any one of the above.

In one aspect of the present invention, the present invention is as follows.
[A1] A method for producing an emulsified tofu coagulant, comprising allowing lipase to act on a coagulant and edible oil.
[A2] The production method according to [A1], wherein the coagulant is one or more selected from the group consisting of magnesium chloride, magnesium sulfate, calcium sulfate, calcium chloride, organic acids, and compositions containing one or more of these. .
[A3] A method for producing soymilk having a property of delaying coagulation, which comprises allowing lipase to act on soymilk.
[A4] The production method according to [A3], wherein the temperature at which the lipase is allowed to act on the soymilk is 50°C to 95°C.
[A5] A method for producing tofu, comprising mixing soymilk and an emulsified coagulant produced by the method according to [A1] or [A2].
[A6] A method for producing tofu, comprising mixing the soymilk produced by the method according to [A3] or [A4] and having a characteristic of delaying coagulation with a coagulant.
[A7] A soymilk produced by the method described in [A3] or [A4] and having a characteristic of retarding coagulation, and an emulsified coagulant produced by the method described in [A1] or [A2]. A method of making tofu, comprising mixing.
[A8] A method for emulsifying a coagulant for tofu, comprising allowing lipase to act on the coagulant and edible oil.
[A9] The method of [A8], wherein the edible oil is at least one vegetable oil selected from the group consisting of rice oil, rapeseed oil, and soybean oil.
[A10] The coagulant is one or more selected from the group consisting of magnesium chloride, magnesium sulfate, calcium sulfate, calcium chloride, organic acids, and compositions containing one or more of these, [A8] or [A9] The method described in .
[A11] A method for delaying coagulation of soymilk, which comprises allowing lipase to act on soymilk.
[A12] The method according to [A11], wherein the temperature at which lipase is allowed to act on soymilk is 50°C to 95°C.
[A13] A composition for retarding coagulation of soymilk for producing tofu, containing a lipase.
[A14] A tofu coagulant comprising a lipase and a coagulant.
[A15] The coagulant for tofu according to [A14], further comprising edible oil.
[A16] The coagulant for tofu according to [A15], wherein the edible oil is at least one vegetable oil selected from the group consisting of rice oil, rapeseed oil, and soybean oil.
[A17] The coagulant is one or more selected from the group consisting of magnesium chloride, magnesium sulfate, calcium sulfate, calcium chloride, organic acids, and compositions containing one or more of these [A14] to [A16] The tofu coagulant according to any one of .

According to the present invention, the coagulant can be emulsified without using an emulsifier. In addition, according to the present invention, soymilk can be prepared which has the characteristic of being delayed in coagulation with respect to a coagulant. Furthermore, by using these emulsified coagulants and modified soymilk in combination, coagulation of soymilk can be suppressed for a long time, so homogeneous tofu can be easily and stably produced. Also, according to the present invention, tofu having a very smooth texture can be produced.

The present invention will be described in detail below.

As used herein, the term "coagulant" means a substance itself or a composition containing the substance that has the effect of cross-linking or denaturing proteins in soymilk and promoting gelation of soymilk in the production of tofu. When the coagulant is a composition, it may contain ingredients other than the above ingredients in addition to a substance that promotes gelation of soymilk. An example of such a coagulant for tofu production is bittern. Bitter juice is a composition containing magnesium chloride as a main component, obtained by precipitating and separating potassium chloride and sodium chloride from seawater. Coagulant products based on purified magnesium chloride (hexahydrate) are commercially available. The coagulant that can be used in the present invention is not particularly limited as long as it can crosslink the proteins of soymilk. In addition to bittern derived from seawater, calcium chloride, magnesium sulfate, and calcium sulfate produced by industrial methods are used. , sodium chloride, glucono delta lactone (gluconic acid) that has been dissolved in water for a sufficient amount of time, compounds such as organic acids such as citric acid, salt that has a milk curdling effect, food ingredients such as vinegar and acidic fruit juice, protein cross-linking enzymes and proteolytic enzymes (milk-clotting enzymes) can be suitably used or used in combination. Especially suitable for fast-acting coagulants such as magnesium chloride, magnesium sulfate, calcium sulfate, and organic acids. In the present specification, the term “organic acid” is not particularly limited as long as it is an acid of an organic compound that can be added to food and can coagulate soymilk in the production of tofu. Examples include delta-lactone (gluconic acid), citric acid, malic acid, oxalic acid, lactic acid, acetic acid (vinegar), acidic fruit juices such as lemon juice, and lactic acid fermentation extracts. Citric acid and acidic fruit juice obtained from citrus fruits such as yuzu and lemon are preferably used.

As used herein, the terms "soymilk coagulates" and "coagulated soymilk" refer to the addition of a coagulant to liquid soymilk, which causes the soymilk to start to solidify, increase the soymilk viscosity, and completely solidify (gel). It means transition to a state in which fluidity has disappeared, and soymilk that has transitioned to this state, respectively. The soymilk used in the present invention is not particularly limited as long as the desired effect of the present invention can be obtained. , simmered soybean soup, bean broth, etc.) and adjusted soymilk. The soymilk used in the present invention has a concentration that can be coagulated like silk, soybean solid content of 7 to 20% by weight, soybean protein concentration of 3 to 10% by weight, and a brix meter commonly used for simple measurement of 8 to 23. Soy milk equivalent to % brix can be suitably used, but is not limited to this.

1. Method for Producing Emulsified Tofu Coagulant The present invention provides a method for producing an emulsified tofu coagulant (hereinafter referred to as "the present (sometimes referred to as "methods for making emulsified coagulants of the invention"). According to the method for producing an emulsified coagulant of the present invention, an emulsified coagulant emulsified with edible oil can be produced relatively easily without using an emulsifier such as polyglycerin fatty acid ester.

Common emulsified coagulants have a so-called W/O (water-in-oil) emulsified structure in which water droplets of an aqueous solution of a coagulant such as bittern are dispersed in fats and oils. By dispersing the coagulant in the oil, the coagulant component (magnesium chloride) is gradually released and acts on the soymilk, resulting in slow and uniform coagulation of the soymilk. The process of producing a typical emulsified coagulant involves the addition of a chemically synthesized emulsifier such as polyglycerin fatty acid ester, but the method for producing an emulsified coagulant of the present invention does not use such an emulsifier, It is characterized by using lipase and/or phospholipase instead. In the method for producing the emulsified coagulant of the present invention, these ingredients can be mixed in any order and under any conditions as long as the emulsified coagulant having the above emulsified structure can be produced using lipase and/or phospholipase instead of the emulsifier.・Mixing is allowed in the method and apparatus. In one embodiment, the main components can be mixed in the following order. That is, first, a liquid coagulant, or water and a solid coagulant are mixed (dissolved/dispersed) in advance, and lipase and/or phospholipase are added to the coagulant and lipase and/or phospholipase. Prepare an aqueous phase consisting of This water phase is then added to the edible oil which becomes the oil phase. By stirring and emulsifying the obtained mixture of the aqueous phase and the oil phase, the lipase and/or phospholipase are allowed to sufficiently act on the glycerides in the edible oil. In order to further stabilize the emulsified composition, re-stirring and re-emulsification may be performed, or the composition may be allowed to stand at an appropriate temperature for a certain period of time. As a result, a W/O emulsified composition having an edible oil as a continuous phase and a coagulant and lipase and/or phospholipase as a dispersed phase can be obtained.

The coagulant used in the method for producing the emulsified coagulant of the present invention is not particularly limited as long as it is a compound that promotes gelation of soy milk. ), inorganic salts such as magnesium and calcium such as magnesium sulfate, calcium sulfate, and calcium chloride, organic acids such as gluconodeltalactone (gluconic acid), citric acid, and compounds such as their calcium and magnesium salts, and natural Materials include salt (sodium chloride) that has a curdling effect, food materials such as vinegar and acidic fruit juice, protein cross-linking enzymes (e.g. transglutaminase, tyrosinase) and proteolytic enzymes (e.g. papain, rennet, etc.) milk-clotting enzyme) and the like. Any one of these coagulants may be used, or two or more may be used in combination. Magnesium chloride and magnesium sulfate are preferable from the viewpoint of texture, flavor, and the like. It is particularly suitable for fast-acting coagulants such as magnesium chloride, magnesium sulfate, calcium sulfate (including particulate calcium sulfate), and fast-acting organic acids.

Also, the edible oil used in the method for producing the emulsified coagulant of the present invention is not particularly limited as long as the desired effect of the present invention can be obtained. Examples include rice oil, soybean oil, rapeseed oil, olive oil and coconut oil. , sesame oil, palm oil, cottonseed oil, corn oil, and safflower oil, or animal oils such as milk fat, beef tallow, lard, chicken fat, and fish oil. be done. Tofu is a vegetable protein food, and from the viewpoint of demand, vegetable oils and fats are preferably used, and rice oil and soybean oil are particularly preferred. In addition, edible oils are edible oils containing wax components without dewaxing treatment called wintering, or edible oils with some wax components left, or artificial edible waxes such as carnauba wax, rice wax, and beeswax. It may be an edible oil containing 0.01 to 20%, preferably 0.1 to 10% wax component, such as an edible oil added with

In addition, the lipase used in the method for producing the emulsified coagulant of the present invention is not particularly limited as long as it is an enzyme preparation that can be added to foods and the desired effect of the present invention can be obtained. , any lipase can be used. The lipase used in the present invention can be prepared and purified by a method known per se, and commercially available ones may also be used. The type of lipase used in the method for producing an emulsified coagulant of the present invention depends on the composition of glycerides in the edible oil used together and substrate specificity of lipase (for example, position specificity of lipase and chain length specificity of fatty acid). characteristics, etc.), etc., and may be appropriately optimized. Without wishing to be bound by theory, lipase acts mainly on glycerides (diglycerides, triglycerides) that constitute edible oils, and hydrolyzes them to produce monoglycerides and diglycerides. Their emulsifying action increases the affinity of oil and water. As a result, it is believed that emulsification of the coagulant is promoted and stabilized. In the present invention, instead of adding a chemically synthesized emulsifier, the oil component is modified by natural enzymatic action.

The activity unit of lipase used in the present invention is measured and defined as follows. A predetermined amount of the sample is weighed, and a sample dilution solution is added to dissolve the sample to obtain a predetermined dilution solution. That is, 4 mL of phosphate buffer and 5 mL of olive oil emulsion are weighed into a flat-bottomed test tube, mixed and allowed to stand at 37° C. for 10 minutes. Add 1 mL of the sample solution to this, shake well, and immediately leave at 37° C. for exactly 30 minutes. After 30 minutes, add 10 mL of ethanol/acetone mixture (1:1) and shake well. Add 10 mL of 0.05 mol/L sodium hydroxide solution and 10 mL of ethanol/acetone mixed solution (1:1), and then add 2 drops of phenolphthalein test solution as an indicator. While stirring, titrate to pH 10.0 with 0.05 mol/L hydrochloric acid using a pH meter to obtain T ₃₀ mL. Separately, measure 4 mL of buffer solution and 5 mL of olive oil emulsion into a flat-bottomed test tube as a blank, add 10 mL of ethanol/acetone mixture (1:1) and mix, then add 1 mL of sample solution or water, and then operate in the same manner _. Obtain mL. One unit (1 unit (U)) is defined as the amount of enzyme that produces 1 μmole of fatty acid per minute under these conditions, and the amount is calculated using the following formula. However, in order to grasp the net concentration of hydrochloric acid, the factor is defined as the true concentration of the standard solution/labeled concentration of the prepared standard solution, and shall follow the reagent information.

In addition, the phospholipase used in the method for producing the emulsified coagulant of the present invention is not particularly limited as long as it is an enzyme preparation that can be added to foods and the desired effect of the present invention can be obtained. , any phospholipase can be used. The phospholipase used in the present invention can be prepared and purified by a method known per se, and commercially available ones may also be used. The type of phospholipase (phospholipase A, B, C, or D) used in the method for producing the emulsified coagulant of the present invention is determined in consideration of the glyceride composition in the edible oil used together, the substrate specificity of the phospholipase, and the like. can be optimized accordingly.

The activity unit of phospholipase used in the present invention is measured and defined as follows. 0.1 ml of the test enzyme solution is mixed with 1.0 ml of the substrate solution and reacted at 37° C. for 10 minutes (purified water is used instead of the test enzyme solution for blanks). After that, 50 μl of the reaction solution was mixed with 0.5 ml of coloring solution A (NEFA C-Test Wako (Wako Pure Chemical Industries)) and allowed to react at 37° C. for 10 minutes. Kojunyaku Kogyo)) 1.0 ml is mixed and reacted for 10 minutes. After the reaction, the temperature is returned to room temperature, the absorbance at 550 nm is measured with a spectrophotometer, and the activity is calculated from the following equation.

Activity (U/g) = (OD550nm-Blank OD550nm) x 1.1 x N
(N: Dilution ratio of test enzyme solution)

The details of the substrate solution are as follows.

Substrate solution: 0.16 ml of 10% w/v Triton X-100 solution, 0.2 ml of 1.0 mol/l calcium chloride solution and 19.64 ml of purified water were added to 1.0 g of L-α-phosphatidylcholine to emulsify and suspend. make it cloudy 15 ml of 1 mol/l Tris-HCl buffer (pH 8.0) is added to 15 ml of this solution.

In the method for producing an emulsified coagulant of the present invention, the conditions for "acting either or both of lipase and phospholipase on the coagulant and edible oil" are particularly Although not limited, the following conditions can be exemplified. First, water and a coagulant (eg, solid magnesium chloride commercially available as a coagulant for tofu) are mixed at normal temperature (15°C to 30°C) at a weight ratio of 1:0.1 to 2 (preferably 1:0. 3 to 1.5, more preferably 1:0.7 to 1.3) to prepare a coagulant dissolved in water (eg, water bittern) (herein, prepared under such conditions The coagulant dissolved in the water is sometimes referred to as "aqueous coagulant solution"). Then, usually 0.000001 to 10,000,000 U, preferably 0.00001 to 1,000,000 U, particularly preferably 0.0001 to 100,000 U of lipase and/or phospholipase are added to the aqueous coagulant solution. Dissolve. Next, a mixed aqueous solution of a coagulant and lipase and/or phospholipase and edible oil are added at a weight ratio of 1:0.1 to 5 (preferably 1:0.3 to 3, more preferably 1:0.5 to 2). ), sufficiently stirred and emulsified using an emulsifier or the like, and usually -20 ° C. to 100 ° C. (preferably 0 ° C. to 100 ° C., more preferably 15 ° C. to 100 ° C.) for about 0 to 100 hours. Leave still. As a result, a W/O type coagulant emulsified by lipase and/or phospholipase without using an emulsifier is prepared. As described above, the conditions, order, method, and device (emulsifier) for mixing and emulsifying water, a coagulant (eg, magnesium chloride, etc.), lipase and/or phospholipase, and edible oil are not particularly limited. can be any different from the example of , or they can all be mixed at the same time. Since bittern and lipase and/or phospholipase are water-soluble in one embodiment, it is preferable to first mix an aqueous coagulant solution (or bittern) and lipase and/or phospholipase, and then add the aqueous solution to oil. . Alternatively, a method may be employed in which the initial preliminary mixing is in an O/W emulsified state, and the phase is changed to a W/O emulsified state in the subsequent main emulsification.
The emulsifier may be a one-pass system, a circulation system, or a multi-stage system that repeats emulsification multiple times. Not limited.

In a preferred embodiment of the method for producing an emulsified coagulant of the present invention, cyclodextrin can be added when the coagulant is emulsified using edible oil and lipase and/or phospholipase. Cyclodextrin is a cyclic oligosaccharide in which 6, 7 or 8 glucoses are linked in a ring, and is called α-cyclodextrin, β-cyclodextrin or γ-cyclodextrin, respectively. Any of α-cyclodextrin, β-cyclodextrin and γ-cyclodextrin may be used in the method for producing the emulsified coagulant of the present invention, but α-cyclodextrin and β-cyclodextrin are particularly preferred. Cyclodextrin can be produced by a method known per se (eg, a method of allowing cyclodextrin synthase to act on starch, etc.), and commercially available products may also be used.

The amount of cyclodextrin added when the coagulant is emulsified using edible oil and lipase and/or phospholipase is not particularly limited as long as an emulsified coagulant having the desired effect can be produced. Usually 0.01 to 1%, preferably 0.02 to 0.8%, more preferably 0.03 to 0.6%, still more preferably 0.03 to 0.4%, particularly preferably 0.03 to 0.4%, based on the weight is 0.04-0.2%. In addition, the timing of acting the cyclodextrin is not particularly limited as long as an emulsified coagulant having the desired effect can be produced, but a production method in which the cyclodextrin is added at the timing of dissolving the coagulant in water is preferred. For example, but not limited to, cyclodextrin can be added to the mixture after mixing the coagulant, edible oil, and lipase and/or phospholipase, or the cyclodextrin can be premixed with the coagulant. lipase and/or phospholipase and edible oil may be added to this mixture.

2. Method for Producing Soymilk Having Delayed Coagulation Property The present invention provides a method for producing soymilk having a property of delaying coagulation, which comprises causing either or both of lipase and phospholipase to act on soymilk (hereinafter referred to as “the method for producing soymilk having the property of delaying coagulation”). (sometimes referred to as a "method for producing soymilk having properties of delaying coagulation").

In the present specification, "soymilk having a property of delaying coagulation" means that when measured under the same conditions, the coagulation rate (or coagulation time) when a coagulant for tofu production such as bittern is added is It means a soymilk that has a characteristic of slowing down (slowing down) compared to ordinary soymilk (soymilk that has not been subjected to physical property modification treatment such as enzyme treatment). There are various measurement methods for evaluating the coagulation rate. For example, a coagulant is added to a predetermined (e.g., 13% brix at 80 ° C.) soymilk, stirred under predetermined conditions, and then solidified using a viscometer. It can be determined by measuring the time until the viscosity of the agent-containing soymilk begins to rise to a predetermined viscosity, or the time until the fluidity disappears and the soymilk stops visually. It is desirable to make a relative evaluation using a standard commercially available emulsified bittern preparation or water bittern as a control test plot. In one aspect, the soymilk having the property of delaying coagulation is usually 15 seconds or more, preferably 30 seconds or more, more preferably 45 seconds or more when coagulated using water bittern, based on normal soymilk. More preferably 1 minute or more, still more preferably 2 minutes or more, even more preferably 2.5 minutes or more, particularly preferably 3 minutes or more, the coagulation may be delayed.

The lipase and/or phospholipase used in the method for producing soymilk having the property of delaying coagulation of the present invention can be the same as those explained in "1. Production method for emulsified coagulant". .

The conditions for "acting lipase and/or phospholipase on soymilk" are not particularly limited as long as the desired effect can be obtained, but the amount of lipase and/or phospholipase added is usually 0.000001 to 10,000,000U per 1 mg of soymilk. , preferably 0.00001 to 1,000,000 U, particularly preferably 0.0001 to 100,000 U of lipase and/or phospholipase are dissolved. When lipase and phospholipase are used in combination, the sum of the unit numbers of each enzyme should be within the above range. The temperature at which lipase and/or phospholipase are allowed to act on soymilk is usually 0° C. to 100° C., preferably 15° C. to 95° C., more preferably 20° C. to 90° C., still more preferably 30° C. to 90° C., still further. It is preferably 35°C to 90°C, particularly preferably 35°C to 85°C. In addition, the time for which the lipase and/or phospholipase is allowed to act on soymilk is 1 second or longer to obtain a modifying effect, preferably 30 seconds or longer, and more preferably 1 minute or longer. Although the upper limit of the time for which lipase and/or phospholipase is allowed to act on soymilk is not particularly limited, since no further improvement effect can be expected even if lipase and/or phospholipase is allowed to act on soymilk for a certain period of time or longer, it is usually 100 hours or less. It is preferably 80 hours or less, more preferably 70 hours or less, still more preferably 60 hours or less, even more preferably 50 hours or less, and particularly preferably 40 hours or less.

The original soymilk used in the method for producing the soymilk having the property of delaying coagulation of the present invention is not particularly limited as long as the desired effects of the present invention can be obtained. It may be foamed soymilk, unadjusted soymilk (including raw soymilk, bean broth, raw soybean paste, boiled soybean paste, etc.) and adjusted soymilk. The soymilk used in the present invention has a concentration that can be coagulated into a silky (pudding-like) form, a soybean solid content of 7 to 20% by weight, a soybean protein concentration of 3 to 10% by weight, and a sugar content meter that is commonly used for simple measurement. Soymilk corresponding to 8 to 23% brix at , can be suitably used, but is not limited thereto. In one aspect, unadjusted soymilk may be preferred from the viewpoint of being able to use soymilk that is fresher and more flavorful. The soymilk may be a soymilk appropriately containing food ingredients such as antifoaming agents, pH adjusters, flavors and seasonings, edible oil, starch, salt, grain flour, paste, and pigments.

3. Method for producing tofu The present invention involves mixing ordinary soymilk that has not been modified with enzymes such as lipase, and an emulsified coagulant produced according to "1. Method for producing an emulsified coagulant". To provide a method for producing tofu, comprising: The present invention also provides the method of mixing soymilk whose physical properties have been modified with lipase and/or phospholipase, which is produced by "2. Method for producing soymilk having properties of delaying coagulation," and a normal coagulant. To provide a method for producing tofu, comprising: Furthermore, the present invention provides soymilk whose physical properties are modified by the action of lipase and/or phospholipase, which is produced by "2. A method for producing soymilk having a characteristic of delaying coagulation", and "1. Emulsified soymilk. A method for producing tofu, comprising mixing with a coagulant emulsified by the action of lipase and/or phospholipase, which is produced by the method for producing a coagulant. Hereinafter, these production methods may be collectively referred to as the "tofu production method of the present invention". In the method for producing tofu of the present invention, coagulation of soymilk is delayed, so compared to ordinary tofu production methods, homogeneously gelled tofu can be produced under various circumstances. Even when mass-producing tofu using a production line or the like, it is possible to stably produce homogeneous tofu. Furthermore, since no specially chemically synthesized emulsifier is used, it is also possible to avoid deterioration in flavor and the like derived from the emulsifier. In addition, it is easily accepted by tofu producers who pursue more natural and original tofu production and by consumers who are highly health conscious. In addition, in the present invention, since various types of bittern and edible oil can be selected, tofu producers can pursue original flavor and economic efficiency, and can differentiate their products.

In the method for producing tofu of the present invention, the soymilk modified with lipase and/or phospholipase or the coagulant emulsified by the action of lipase and/or phospholipase are used instead of ordinary soymilk and coagulant. can use any conventional tofu manufacturing process or manufacturing technique.

In one aspect, the method for producing tofu of the present invention can be carried out in an integrated manner with the method for producing soymilk/tofu having the property of retarding coagulation of the present invention, regardless of whether it is a continuous method or a batch method. Although it is not limited to this, for example, the following embodiment is exemplified as one aspect of continuous production of tofu using a production line. First, soy milk is placed in a temperature-controllable tank and heated to 50°C to 95°C (more preferably 60°C to 90°C, still more preferably 70°C to 90°C, still more preferably 75°C to 85°C, still more (preferably 77°C to 83°C, particularly preferably 78°C to 82°C). A required amount of lipase and/or phospholipase is added to this soymilk tank, or pumped from the soymilk tank to the middle of the piping for feeding soymilk by a soymilk pump, and stirred sufficiently for 1 minute while maintaining the temperature of the soymilk. The enzymatic reaction is allowed to stand still (preferably for 3 minutes, more preferably 5 minutes), or, if necessary, while stirring in a soymilk balance tank with stirring, or while flowing through the holding pipe on the liquid delivery pipe. to prepare lipase and/or phospholipase modified soymilk. In addition, in a separate temperature-controlled coagulant tank (for example, with a jacket that allows indirect cooling and indirect heating, and equipped with a stirrer), a coagulant for tofu production (emulsified or non-emulsified) It is preferable to cool and keep warm at room temperature or at 30°C or less. Injection/mixing/dispersing devices for quantitatively injecting/mixing/dispersing the coagulant into the lipase and/or phospholipase-modified soymilk on which the lipase and/or phospholipase acted under predetermined conditions (respectively, a metering pump, a flow meter, and a PID) It is preferably provided with a static mixer such as a static mixer, or an emulsifying and dispersing device such as a high-speed rotary mixer consisting of a rotor and a stator, or a high-pressure homogenizer, etc.). Mold into silken tofu. The coagulation and maturing tank may be a rectangular parallelepiped rectangular box or a cylindrical coagulation container, or a belt-type continuous coagulation and molding device having a concave cross section. For continuous molding, soymilk and coagulant are injected and mixed at one end of the vessel. The soymilk mixed with a coagulant at one end of the coagulation and maturation tank is gradually moved to the opposite end of the coagulation and maturation tank and continuously coagulated and matured to form a sheet-like silken tofu. In the case of firm tofu, the sheet-like silken tofu is appropriately crushed by a crushing device, transferred to a continuous molding device, and compression-molded. Therefore, the distance between the end where soymilk and coagulant are injected and mixed in the coagulation and maturation tank and the opposite end may be appropriately determined according to the coagulation and maturation time and capacity of soymilk. The tofu that has been completed in the coagulation and maturing tank is cut into appropriate sizes, put into packaging packs or the like, and enclosed. As one aspect of batch production, the soymilk prepared in the soymilk tank is weighed into a coagulation container (cylindrical bucket, cuboid mold box, etc.), and the emulsified coagulant prepared in the coagulant tank is weighed. Add to the soymilk in the coagulation container, stir the soymilk containing the coagulant under predetermined conditions with a stirring device (for example, a high-speed rotary mixer consisting of a rotor and a stator), then allow to stand and ripen to form silken tofu-like coagulum. get In the case of cotton tofu, the silken tofu-like coagulum in the coagulation container is appropriately crumbled, placed in a perforated cotton box covered with cloth, and pressed.

4. A method for emulsifying a tofu coagulant using lipase and/or phospholipase The present invention provides a method for emulsifying a tofu coagulant (hereinafter referred to as " (sometimes referred to as "the emulsification method of the present invention"). In one aspect, the emulsification method of the present invention may further incorporate cyclodextrin. According to the emulsifying method of the present invention, an emulsified composition can be prepared from more natural and simple materials such as a coagulant, edible oil and enzyme without using a chemically synthesized emulsifier such as a polyglycerin fatty acid ester. can be done.

The coagulant, edible oil, lipase, phospholipase, cyclodextrin used in the emulsification method of the present invention, and their action conditions, etc. are the same as those described in "1. Production method of emulsified coagulant". can use things.

5. Method for delaying coagulation of soymilk using lipase and/or phospholipase (sometimes referred to as "coagulation retardation methods"). According to the method for delaying coagulation of soymilk of the present invention, the coagulation speed (or coagulation time) of soymilk by a soymilk coagulant for producing tofu, such as bittern, is delayed compared to the coagulation speed (or coagulation time) of ordinary soymilk. becomes possible.

The lipase, phospholipase, lipase and/or phospholipase used in the method for delaying coagulation of soymilk of the present invention are described in "2. Method for producing soymilk having properties of delaying coagulation". can be used.

6. Composition for delaying clotting of soymilk The present invention provides a composition for delaying clotting of soymilk (hereinafter sometimes referred to as "the composition for delaying clotting of the present invention") containing either or both of a lipase and a phospholipase. do. By adding the composition for delaying coagulation of the present invention to soymilk, the physical properties of soymilk are modified, and as a result, the speed (or time) of coagulation of soymilk by a coagulant such as bittern can be delayed.

The lipase and/or phospholipase contained in the composition for delaying coagulation of the present invention can be the same as those explained in "1. Production method of emulsified coagulant". In addition, the blending amount is not particularly limited as long as the desired effect can be obtained, but usually 0.000001 wt% to 99.9 wt%, preferably 30 wt% to 99.9 wt%, more preferably 50 wt% ~99.9% by weight, more preferably 70% to 99.9% by weight, particularly preferably 90% to 99.9% by weight.

In addition, the form of the composition for delaying coagulation of the present invention is not particularly limited as long as the desired effect can be obtained. can be prepared in the form

The composition for delaying coagulation of the present invention can also contain components other than lipase and/or phospholipase. Such ingredients include, for example, additives other than coagulants commonly used in the production of tofu (e.g., stabilizers and alkaline pH adjusters), and ingredients capable of retaining and/or enhancing the activity of lipase and/or phospholipase. etc., but not limited to these.

Conditions for adding the composition for delaying coagulation of the present invention to soymilk can be determined by those skilled in the art by referring to the conditions described in “2. It can be determined as appropriate.

7. Coagulant for tofu The present invention provides a coagulant for tofu (hereinafter sometimes referred to as "the coagulant for tofu of the present invention") comprising an enzyme, a coagulant, and the like. Specifically, the tofu coagulant of the present invention is a tofu coagulant comprising lipase and/or phospholipase and a coagulant, or lipase and/or phospholipase, edible oil and a coagulant. In one aspect, the tofu coagulant of the present invention may further contain cyclodextrin. By adding the tofu coagulant of the present invention to soymilk, the coagulation speed (or coagulation time) of soymilk is delayed compared to usual soymilk, and it becomes possible to coagulate soymilk slowly and uniformly.

The lipase, phospholipase, edible oil, coagulant, and cyclodextrin that can be blended in the tofu coagulant of the present invention can be the same as those explained in "1. Production method of emulsified coagulant". .

The form of the tofu coagulant of the present invention is not particularly limited as long as the desired effect can be obtained. can do. For example, when producing a solid tofu coagulant, each main ingredient may be pulverized by a method known per se and mixed.

The present invention will be described in more detail in the following examples, but the present invention is not limited by these examples.

[Example 1] Coagulation retarding effect of coagulant emulsified using lipase It was examined whether a coagulant emulsified with edible oil using lipase without using an emulsifier can delay coagulation of soymilk. As a coagulant, bittern ("soft wafer (magnesium content is a standard value of 95% by weight or more as MgCl.6H ₂ O, an analytical value of 99.9% by weight or more)" manufactured by Ako Kasei Co., Ltd.) is used to emulsify according to the following procedure. Bitter juice was prepared. First, water bittern was prepared by mixing bittern and water in a weight ratio of 1:1 and dissolving bittern in water. One of two commercially available lipases (Sample A: Enzyme activity 150000 U / g, Sample B: Enzyme activity 500000 U / g) was added to this water bittern at three concentrations (0.03 U / 1 g oil (0.36 U as a whole) ), 0.3 U/1 g oil (3.6 U overall), 3 U/1 g oil (36 U overall)). The temperature of the water bittern when the lipase was added was 50°C. Next, water bittern containing lipase and rice oil ("Komeshibori" (manufactured by Kitoku Shinryo Co., Ltd.)) were mixed at a weight ratio of 6:4, and emulsified by vigorously stirring. Specifically, 9 g of bittern, 9 g of water, and 12 g of rice oil were mixed to make a total of 30 g, and further stirred at 13500 rpm for 180 seconds using "Labo Solution" (Primix Co., Ltd.). , water bittern containing lipase and rice oil were mixed. Next, in order to allow the lipase to act sufficiently, the mixture was allowed to stand at 20° C. for 16 hours to obtain lipase-emulsified bittern (compositions of various prepared bittern are shown in Table 1). The concentration of magnesium chloride in these lipase emulsified bittern is 30% by weight. 300 mg of these lipase emulsified bittern was added to soymilk (30g) heated to 90°C so that the magnesium chloride concentration was 0.3% by weight based on the soymilk, and the time for the soymilk to solidify was measured using a stopwatch. This trial was performed twice. In addition, unemulsified bittern (control 1), or lipase-free bittern mixed with only rice oil (control 2) was added to soymilk under the same conditions as the lipase emulsified bittern, and the soymilk was coagulated. It was used as a comparison target for delay. Table 1 shows the results. In addition, the coagulation time shows the average value of two measurements.

As shown in Table 1, both lipase-emulsified bittern delayed the coagulation of soymilk compared to water bittern (control 1).

[Example 2] Modification of soymilk with lipase and examination of effect of combined use of modified soymilk and lipase emulsified bittern In addition to emulsification of the coagulant with lipase, the effect of retarding coagulation was examined when soymilk was modified with lipase. Soymilk was heated to 85° C., and 0.1 mg (0.01% by weight of soymilk) of commercially available powdered lipase (sample B: enzyme activity 150,000 U/g) was added per 1 g of soymilk (30 g). Mixed. While maintaining the temperature at 85° C., the soymilk and lipase were allowed to react for 5 minutes (lipase-modified soymilk). Water bittern or emulsified bittern using lipase (lipase emulsified bittern) was added to lipase-modified soymilk, and the coagulation time was measured. In addition, as comparison subjects, an embodiment in which bittern was added to normal soymilk (Control 1), an embodiment in which a mixture of bittern and rice oil was added to normal soymilk (Control 2), and bittern to lipase-modified soymilk was added. Each added embodiment was used. The lipase emulsified bittern was prepared by the method described in Example 1 (the lipase used was sample B: enzyme activity of 500,000 U/g). Table 2 shows the results. The coagulation time is the average of two measurements obtained by performing the same test twice. Moreover, the texture (“smoothness”) of the tofu prepared under each condition was evaluated by a sensory test by four expert panels. As the evaluation criteria for "smoothness", smoothness was evaluated when no particles remained when rubbed with the upper jaw and tongue. The "smoothness" of the tofu prepared under the conditions of Control 1 was 1 point (standard), 1 point (normal smoothness), 2 points (slightly smoother than usual), 3 points (smoother than usual), 4 points ( Evaluation was made on a 9-point scale of 0.5 points from 5 points (more smooth than usual) to 5 points (very smoother than usual). The score was shown as the average score evaluated by each specialized panel.

As shown in Table 2, the lipase-modified soymilk delayed coagulation for 3 minutes compared to Control 1, indicating that it possessed the property of retarding coagulation. In addition, it was shown that the combined use of lipase-emulsified bittern and lipase-modified soymilk further extended the coagulation retarding effect of soymilk. In addition, lipase-modified soymilk, lipase-emulsified bittern, or tofu prepared by using them in combination has a smoother texture than tofu prepared using normal bittern and soymilk (Control 1). was

[Example 3] Examination of lipase action temperature In order to examine a more preferable temperature for acting lipase on soymilk, the temperature for acting soymilk and lipase in Example 2 was changed from 85 ° C. to 80 ° C., and the same experiment and made an evaluation. The results are shown in Table 3 below. The coagulation time is the average of two measurements obtained by performing the same test twice.

As shown in Table 3, the lipase-modified soymilk still had a 0.5 minute clotting delay property compared to Control 1, even when the lipase working temperature was changed to 80°C. The soymilk modified with lipase at a temperature of 80° C. had a very remarkable coagulation retarding effect when used in combination with lipase emulsified bittern, although the coagulation retarding effect itself was not so high. Furthermore, the tofu prepared using both lipase-modified soymilk and lipase-emulsified bittern had a remarkably smoother texture than the control 1 tofu.

[Example 4] Examination of the type of lipase It was examined whether the type of lipase might affect the effects of the present invention. In the process of preparing lipase emulsified bittern in Example 1, the lipase was changed to another type of lipase (Sample C: enzymatic activity 30000 U/g), and the other conditions were the same as in Example 1 to prepare lipase emulsified bittern. prepared. In addition, among the experimental conditions of Example 3, the lipase was changed to another type (Sample C) to modify the soymilk, and using these, the effects on retardation of coagulation and texture were examined. Table 4 shows the results. The coagulation time is the average of two measurements obtained by performing the same test twice.

Even when the type of lipase was changed, soymilk could be modified, and by using lipase-emulsified bittern and lipase-modified soymilk in combination, a favorable coagulation retarding effect was obtained.

[Example 5] Coagulation retarding effect of coagulant emulsified using phospholipase , and other conditions similar to those of Example 1 to prepare a phospholipase emulsified bittern. Table 5 shows the coagulation time of soymilk when soymilk was coagulated using the prepared phospholipase emulsified bittern.

As shown in Table 5, clotting time could also be delayed using phospholipase instead of lipase.

[Example 6] Coagulation retarding effect of coagulant emulsified by combining phospholipase and cyclodextrin In the preparation process of lipase emulsified bittern in Example 1, lipase was replaced with phospholipase A (sample D: enzyme activity 100,000 U/g). Then, emulsified bittern was prepared under the same conditions as in Example 1, except that cyclodextrin (α-cyclodextrin) was additionally added. The amount of phospholipase added was 0.36U. The amount of cyclodextrin added is shown in "%" with respect to the weight of the aqueous coagulant solution. Table 6 shows the coagulation time of soymilk when soymilk was coagulated using the prepared emulsified bittern containing phospholipase combined with cyclodextrin.

As shown in Table 6, it was shown that the concomitant use of cyclodextrin could further delay the clotting time.

[Example 7] Modification of soymilk with phospholipase and study of combined effect of modified soymilk and phospholipase emulsified bittern Phospholipase-modified soymilk and phospholipase emulsified coagulant were prepared using similar conditions and used to measure clotting times. Table 7 shows the results.

As shown in Table 7, it was possible to prepare soymilk with the property of retarding coagulation even with the use of phospholipase.

According to the present invention, a coagulant for producing tofu can be emulsified without using a specially added emulsifier. In addition, according to the present invention, soymilk can be prepared which has the characteristic of being delayed in coagulation with respect to a coagulant for producing tofu. Furthermore, by using these emulsified coagulants and coagulation retarded soymilk in combination, it is possible to stably mass-produce homogeneous and very smooth tofu in spite of not using emulsifiers. Therefore, the present invention is useful in the field of food manufacturing.

Claims (17)

A method for producing an emulsified coagulant for tofu, comprising allowing either or both of a lipase and a phospholipase to act on a coagulant and an edible oil. 2. The production method according to claim 1, wherein the coagulant is one or more selected from the group consisting of magnesium chloride, magnesium sulfate, calcium sulfate, calcium chloride, organic acids, and compositions containing one or more of these. 3. The production method according to claim 1 or 2, further comprising allowing cyclodextrin to act. A method for producing tofu, comprising mixing soymilk and an emulsified coagulant produced by the method according to any one of claims 1 to 3. Soymilk having the property of retarding coagulation produced by the action of either or both of lipase and phospholipase on soymilk , and emulsified coagulated produced by the method according to any one of claims 1 to 3. A method for producing tofu, comprising mixing with an agent. A method for emulsifying a coagulant for tofu, comprising allowing either or both of a lipase and a phospholipase to act on the coagulant and edible oil. 7. The method of claim 6 , further comprising acting with cyclodextrin. 8. The method according to claim 6 or 7 , wherein the edible oil is at least one vegetable oil selected from the group consisting of rice oil, rapeseed oil, and soybean oil. 9. Any one of claims 6 to 8 , wherein the coagulant is one or more selected from the group consisting of magnesium chloride, magnesium sulfate, calcium sulfate, calcium chloride, organic acids, and compositions containing one or more of these. described method. A method for delaying coagulation of soymilk, comprising allowing either or both of lipase and phospholipase to act on soymilk. The method according to claim 10 , wherein the temperature at which either one or both of lipase and phospholipase are allowed to act on soymilk is 50°C to 95°C. A composition for slowing the coagulation of soymilk for making tofu, comprising either or both of a lipase and a phospholipase. A coagulant for tofu, comprising either or both of a lipase and a phospholipase, and a coagulant. 14. The tofu coagulant of claim 13 , further comprising edible oil. 15. The tofu coagulant according to claim 13 or 14 , further comprising cyclodextrin. The coagulant for tofu according to any one of claims 13 to 15 , wherein the edible oil is at least one vegetable oil selected from the group consisting of rice oil, rapeseed oil and soybean oil. 17. Any one of claims 13 to 16 , wherein the coagulant is one or more selected from the group consisting of magnesium chloride, magnesium sulfate, calcium sulfate, calcium chloride, organic acids, and compositions containing one or more of these. Coagulant for tofu described.